Bundling machines



June Z, 1970 F. P. JOHNSON 3,515,056

BUNDLING MACHINES Filed March l2, 1968 7 Sheets-Shee l June Z, 1970 F.P. JOHNSON 3,515,056

BUNDLING MACHINES Filed March 12, 196e 7 sheets-sheet a June 2, 1970 F.P. JOHNSON 3,515,056

BUNDLING MACHINES Filed March 12. 1968 7 SheeLs-Shee?l 5 rf 1 Y FIG. 3

June 2, 1970 F. P. .JOHNSON BUNDLING MACHINES 7 Sheets-Sheet L FiledMarch 12. 1968 NGN June 2, 1970 F. P4. JOHNSON 3,515,056

BUNDLI'NG MACHINES Filed March 12, 1968 7 sheets-sheet s FIG, 5

vJune 2, 1970 F. P. JOHNSON 3,515,056

BUNDLING MACHINES Filed March 12, 1968 7 Sheets-Sheet 6 June 2, 1970 F.P. JOHNSON 3,515,056

BUNDLING MAcHINEs Filed March 12, 1968 7 Sheets-Sheet 7 @UVE/235 FIG. 7

United States Patent O 3,515,056 BUNDLING MACHINES Frederick PaulJohnson, Manchester, England, assignor to Henry Simon Limited, CheadleHeath, England, a British company Filed Mar. 12, 1968, Ser. No. 712,500Claims priority, application Great Britain, Mar. 16, 1967, 12,282/ 67Int. Cl. B65b 13/20 U.S. Cl. 100-4 12 Claims ABSTRACT F THE DISCLOSURE Amachine for tying bundles of articles together in which a bundle ofarticles is conveyed to a tying mechanism at which its movement isarrested. The tying mechanism is operated by a sensor -to tie thestationary bundle and when tied the bundle of articles is delivered out0f the machine.

This invention relates to article tying machines,

In particular it relates to a machine for tying articles such as bundlesof stacked boxboard carton blanks by conveying the articles insuccession into and out of a tying unit forming part of the machine.

In a known form of article tying unit a closed loop of twine is formedaround an article by the vmanual movement of an article into an openloop of the twine and then by the downward lmovement of a needlecarrying the twine bringing together two adjacent portions of the twine,which adjacent portions are clamped together by a metal clip formed bythe unit from a reel of metal strip. Such a tying unit is the subject ofBritish Pat. No. 947,093 (Hood), and is referred to hereafter in thisspecification as a tying unit of the kind specified.

It is an object of the present invention to provide a method of `tyingarticles by conveying the articles automatically and in succession intoand out of a tying unit, for example a tying unit of the kind specified.

It is a further object of the invention to provide an article tyingmachine adapted for continuous in-line operation and incorporating atying unit, for example a tying unit of the kind specified.

Requirements which may arise in the automatic conveying of articles intoand out of a tying unit include (a) the positive holding of an articlewhile it is being tied, (b) the precise location of a stationary articleat a tying station in the machine and (c) the ability to handle articlesvarying to some extent in height or length or configuration.

According to the present invention there is provided a method of tyingarticles passing in succession into a tying machine, and including thesteps of conveying an article into the machine, stopping the article ata tying station in the machine, tying the article, and conveying thearticle out of the machine.

More particularly, it is preferred to employ in the method a tyingmachine incorporating a tying unit of the kind specified, the methodincluding the steps of positively holding and conveying an article intothe machines, sensing the passage of a trailing extremity of thearticle, stopping the article at a tying station in the machine whensaid trailing extremity of the article is at a predetermined location inthe machine, tying the article, and conveying the article out of themachine.

Also according to the present invention there is prov ided an articletying machine, Vcomprising conveyor means adapted to convey articlesthrough the machine, a tying station within the run of said conveyors,tying means adapted to tie an article located at said tying station, asensor adapted to sense the passage of an article ice and to stop saidconveyors when the article is at the tying station, and means operableto restart the conveyors when the article has been tied.

More particularly, it is preferred that the article tying machine beadapted for in-line operation, and comprise an upper and lower conveyoradapted positively to hold and to convey an article linearly through themachine, a tying station within the run of said conveyor means, a tyingunit of the kind specified adapted to tie an article located at saidtying station, a sensor adapted to sense the passage of a trailingextremity of the article and to emit a stop signal operative to stop theconveyor means when said trailing extremity of the article is at apredetermined location relative to the line of action of the needle ofsaid tying unit, and means operative to restart the conveyor means whenthe article has been tied.

Embodiments of the present invention will now be described, by way ofexample, with reference to the accompanying drawings, in which:

FIG. 1 shows a general arrangement in side elevation of a bundle tyingmachine in accordance with the present invention;

FIG. 2 is an enlarged view of parts of FIG. 1;

FIG. 3 is a cross section on the line 3-3 of FIG. 1;

FIG. 4 is a diagrammatic side elevation of a modified construction ofbundle tying machine;

FIG. 5 is a detail view, to an enlarged scale, of parts of FIG. 4;

FIG. 6 is a diagram of the hydraulic circuit of the tying machine ofFIGS. 4 and 5; and

FIG. 7 is a diagram of the pneumatic circuit of the tying machine ofFIGS. 4 and 5.

The machine of FIGS. 1 to 3 is a bundle compressing and tying machineadapted for continuous in-line operation, and is intended to receive andtie bundles of box board carton blanks passed in succession into themachine.

Referring now to FIGS. 1 to 3 of the drawings in particular the machinecomprises an upper conveyor 10 and a lower conveyor 12, both mounted ona frame. At a location along the run of the conveyors 10 and 12 therevisdisposed a tying unit comprising a needle assembly 14 located above theupper conveyor -10 and a clipping assembly 16 located below the lowerconveyor 12. Also disposed below the lower conveyor 12 is a hydraulicunit 18 which actuates the needle assembly 14 Aand the clipping assembly16, and an electrical control box I20 from which the operating sequenceof the machine is controlled.

The frame of the machine is mounted onfour pulleys 22 which run on twoinverted angle iron rail-s 24 to permit sideways adjustment of theposition of .the machine with respect to the position of bundles beingfed into the machine.

The lower conveyor 12 comprises two spaced endless strip conveyor belts26 (FIG. 3) runningon a series, of rollers 28, the bels 26 being drivenbya drive motor 30 having a brake 32 incorporated therein. The lowerconveyor 12 is rigidly secured to the frame kof themachinle.

The upper conveyor 10 comprises twospaced endless strip conveyor belts34 (FIG. 3) running over ,aseries of rollers 36, the belt 34 beingdriven by-:a drive vmotor 38 incorporating a brake 40. Theupper conveyor1,0 is adapted for vertical movementl on two-vertical arms 42 attachedto the frame. Rollers 44 are attached-` to veach of the two horizontalarms .46 supporting-the upper conveyor, and roll on vertical runways 45attached to the vertical arms 42. n

Upward and downward movement ofthe upper conveyor 10 is controlled bytwo conveyor lifting assemblies, the parts of which will now bedescribed. Above each of two horizontal arms 48 (FIGS) rigidly attached4to the vertical arms 42, there is mounted a linkage including jointedbars 50, 52, a rod 54 partly screw thraeded and adapted to slide in abore in the horizontal arm 48, a pneumatic lift cylinder 56, a handwheel58 and a spring 60. The handwheel 58 is secured to a bush 59 which isscrew threadedly rotatable on the screw threaded portion of the rod 54.The cylinder 56 is a double acting cylinder, and air supply to the lowerside of its associated piston is via an inlet 62, while air supply totheupper side of the piston is by an inlet line 64 which includes apressure gauge 65 and an adjustable constant pressure outlet valve 66.The piston of the pneumatic lift cylinder 56 is attached by means of apiston rod and knuckle joint to the bar 52 of the linkage.

Admittance of air through the inlet 62 of each conveyor lifting assemblyserves to raise the upper conveyor clear of the maximum height ofbundles to be passed through the machine. Admittance of air through theinlet 64 causes the upper conveyor to be moved in a downward directionto exert a predetermined pressure on bundles passing through themachine, by suitable settings of the adjustable valve 66 and thehandwheel 58.

Actuation of the handwheel 58 adjusts the height of the upper conveyorl10 above the lower conveyor 12 to a suitable height to receive bundlesto be passed through the machine.

An upwardly angled entry conveyor 68 serves to receive bundles enteringthe machine. The entry conveyor 68 includes three spaced strip conveyorbelts 70 running over four rollers. The belts 70 of the entry conveyor68 are arranged to run at a slightly higher speed than that of the belts34 of the upper conveyor 10 and the belts 26 of the lower conveyor 12.This result is achieved by arranging that drive to the belts 70 of theentry conveyor 68 is from -stepped sections of an end roller 37 of theupper conveyor 10, the stepped sections having a diameter greater thanthe diameter of those sections over which the belts 34 pass. By thismeans any tendency for the angled entry conveyor 68 to retard upperblanks of a bundle is minimised.

The angled entry conveyor `68 is arranged to swivel about the axis ofthe end roller 37, under the action of a spring 72, the arrangementproviding that upward movement of the conveyor 68 compresses the spring72.

The needle assembly 14 and clipping assembly 16 form part of acommercially available bundle tying unit, the subject of theaforementioned British Pat. No. 947,093. The needle assembly 14 includesan eyed needle 80 which carries twine 82 which is supplied to the needlefrom a twine reel 84, the needle being arranged for near-verticalmovement by hydraulic actuation. In a modication of the unit, the needleis pneumatically operated.

From a clip metal reel 86 a strip of metal 88 is fed to the clippingassembly 16. The clipping assembly 16 includes a hydraulically operatedclipper rarn 910 and an anvil 92 which co-operate to form a metal cliparound two adjacent portions of twine within the clipping assemblytheclip being formed from the metal strip 88. The clipping assembly alsoincludes means to sever twine at a position below the formed metal clip.Actuation of the ram 90 is from a hydraulic cylinder 91 through apivoted arm 93. n In the operation of the machine, a bundle 94 entersthe space between the entry conveyor 68 and the lower conveyor 12 andiscarried through the conveyors 10 and 12. During the movementof thebundle past the needle assembly 14, the leading face of the bundle meetsa length of twine extending from the needle to the clipping assembly andcarries this twine forward with it until the upper and lower sides ofthe bundle as well as its leading face become lfolded in a loop of twine83, the twine running from the twine supply reel through the eye of theneedle 80. `A lower end of the twine loop 83 is attached in the clippingassembly.

The bundle now reaches a tying station when a trail- Ving extremity 96of the bundle has passed to a predetermined distance beyond the line ofaction 98 of the needle (FIG. 2). Under the action of control means tobe described, the two conveyor motors 30, 38 are braked thus stoppingthe conveyors 10, 12 and 68 when the bundle is at the tying station.

At this stage the needle descends to pass the twine round the trailingface of the bundle and to form two adjacent portions of twine in theclipping assembly round which portions a metal clip is formed andsecured, the metal forming the clip being first severed from the strip88. Following this operation, the twine 82 is severed below the clip.

The needle now ascends to its raised position shown in FIG. 1, the twoconveyor drive motors 30, 38 are started, and the tied bundle proceedsalong the remainder of the conveyor run and emerges from the machine.

The hydraulic unit 18 which provides hydraulic power for the movement ofthe needle 80 and of the clipping and severing mechanism comprises anelectric motor 100 driving a hydraulic pump 102, supply of hydraulicfluid to which is from a ten gallon reservoir 104. The unit alsocomprises a pressure gauge 106.

The sequence of operation of various parts of the machine are controlledby limit switches, relays and a photoelectric cell forming part ofelectrical circuitry of the machine.

A light source 108 (FIG. 2) is arranged in the run of the lowerconveyor, and a photo-electric cell 110 is mounted above the upperconveyor and vertically above the light source 108. The light source isarranged to direct a light beam on to the photo-electric cell 110,'which beam is interrupted by the passage of a bundle 94 through themachine prior to its reaching the tying station. The photo-electric cellacts as a sensor adapted to sense the passage of a bundle or a part of abundle passing beneath it.

Three limit switches 112, 114 and 116 (FIG. 2), are' located with theiroperating levers or rollers projecting slightly beneath the upperconveyor 10` so that they are actuatedv by the passage of a bundle. Afurther limit switch 118 is located with its operating lever projectingslightly above the lower conveyor 12. A limit switch 120 (FIG. 1) ismounted in conjunction with the needle assembly 14 and is actuated bythe needle upon its descent.

Within the clipping assembly, forward motion of the clipper ram 90operates a limit switch 122. Return motion of the clipper ram operates afurther limit switch A limit switch 126 (FIG. 3) is located in the runof the twine 82, and is operated if the twine breaks or if the twinesupply 84 runs out.

Within the control box 20 is situated a solid state timing device, and adial 128 located on the panel of the control box 20 permits variation ofa delay period provided by the timing device.

'I'he function of the photo-electric cell 110` is to pass a signal tothe timer when the trailing extremity 96 (FIG.

2) of a moving bundle 94 moves clear of the light beam. Following apredetermined time delay set on the timer dial 128, the two conveyordrive motors 30, 38 are braked and the bundle is stopped at the tyingstation. y

In order to achieve the most satisfactory results from the tying unit itis advisable that the trailing face of a bundle is stopped as near vaspossible to the line of action 98 of the needle 80, since the greaterthe separation of these elements the less tightly will the bundle betied. It is also necessary that the bundle should not be stopped beforeits trailing extremity have moved passed the line of action of theneedle, otherwise the needle will penetrate at least part of the bundle.e

In an initial run of `bundles through the machine, the timer is set to avalue which provides a satisfactory separation of the trailing face ofeach bundle from the line of action of the needle. In some cases themachine may receive a bundle which has not been carefully stacked, sothat, for example, some of the blanks in the bundle are projectingbeyond the rest of the blanks at the trailing face of the bundle.Thiscondition is illustrated in FIGS. 1 and 2. Since the signal from thephoto-electric cell 110 is initiated by the trailing extremity of thebundle, i.e. that part which projects to the greatest extent from thetrailing face of the bundle, it will be realised that the method ofsensing by photo-electric cell is able to take account of irregularitiesat any level in the staking of individual bundles.

To achieve a desired tightness of tying of the bundles, it is necessarythat these be compressed while they are tied. Also, during the tyingoperation considerable forces are exerted on a bundle, so each bundlemust be positively held between the conveyors while it is at the tyingstation. Such compression and positive holding is achieved by the actionof the two pneumatic lift cylinders 56 which cause the upper conveyor 10to exert a downward force on the bundles as they pass through themachine. The vertical movement of the upper conveyor 10 also permits themachine to handle bundles having some variation in height.

The angled entry conveyor 68 which is hinged to the conveyor 10 permitssome variation of the angle between the conveyors 68 and 10, but a limitswitch 130 (FIG. 1) which is arranged to be operated by undue upwardmovement of the conveyor 68 acts as a safety device to brake theconveyor drive motors 30, 38 if an oversized object attempts to enterthe machine.

The operation of the machine will now be described in more detail, toinclude the operating sequence of the limit switches.

OPERATING SEQUENCE (l) A bundle 94 enters the machine and the light beamto the photo-electric cell |110 is broken. This resets a relay (notshown) in the control box 20 associated with the photo-electric cellcircuit.

(2) Limit switch 112 is operated by the bundle leading edge, andprepares the photo-electric cell 110I to take control of the conveyormotors 30, 38.

(3) The trailing face of the bundle passes clear of the light beam, andthe photo-electric cell initiates a timing sequence, the timing periodbeing dependent on the setting of the timer dial 128.

(4) The limit switches 114 and 118 are operated by the bundle, and serveto prevent the needle 80 from descending while the bundle is passingunder the needle.

(5) Limit switch 116 is operated by the bundle leading edge. This limitswitch is in the same circuit as limit switch i112, which is then closedby passage of the bundle trailing edge.

(6) The pre-set timer period ends, and the conveyor drive motors 30, 38are braked to bring the bundle to rest at the tying station.

(7) Limit switches 114 and 118 are released by the trailing edges of thebundle, a solenoid valve (not shown) is energised and hydraulicactuation of the needle commences. The needle thus begins to descend.

(8) When the needle reaches the bottom of its stroke, limit switch 120is operated to energise a further solenoid valve (not shown) whichinitiates forward motion of the `clipper ram 90 of the clipping assembly16.

(9) At the end of the clipper ram stroke, limit switch 122 operates andserves to stop the forward motion of the ram, to initiate a returnstroke of the ram and to cause a blast of air to be directed to theclipper mechanism for the purpose of clearing the mechanism of loosetwine.

(10) At the end of the clipper rams return stroke, limit switch 124 isoperated and the two solenoid valves previously referred to arede-energised. The needle now ascends and the air blast is cut off.

(11) Limit switch 120 is released as the needle ascends, and this causesthe conveyor motors 30, 38 to start up.

(12) 'Ihe bundle is conveyed out of the machine, and the trailing edgereleased limit switch 116 serving to reset relays in the control circuitready for a further sequence of operations in association with the nextbundle.

For the machine described, this sequence of operations covers bundles ofbelow a specied length. When the machine handles longer bundles, thesequence of operations of the photo-electric cell and limit switches 112and 116 varies, but the result is the same in terms of machineperformance.

Reference is now made to FIGS. 4 to 7 of the drawings. In thisembodiment, the machine is a free standing unit, being tted with castorwheels 200 for movement. It is provided with bayonet connectors of knownconstruction (not shown) for the necessary compressed air andelectricity services. If desired, an air compressor may be built intothe machine so that only an electricity connection is required.

The machine has a regid fabricated base constituted by an oil tank of,for example, thirty gallons capacity mounted on the castors 200, whichare of roller bearing form and which permit vertical adjustment of themachine, for example three inches.

Four rectangular section members 202 secured together and carried byuprights 203 of the base support a lower conveyor 204. The conveyor 204has two side-byside belts 205 supported on rollers 206 and/or otherknown convenient supports, for example flat plates. The conveyor 204 isdriven by a hydraulic motor of known construction (not shown) which isin hydraulic communication with the tank 20-1.

It will be manifest that due to the vertical adjustability of thecastors 200 the maximum horizontal height of conveyor 204 is threeinches higher than its minimum horizontal height. It will also bemanifest that by an uneven adjustment of the castors 200 the conveyor204 can be tilted to give different lead-in heights.

A substantial vertical column 207 is fixed to the base and supports acantilevered member 208 which carries an upper conveyor 209 and whichhouses a pneumatic cylinder V210-, linkage 211 and -a sliding guide 212for the upper conveyor 209. The latter is similar to lower conveyor 204,that is, it has two side-by-side endless belts 213 supported on rollers214 or other known convenient supports (not sho-wn), for example Hatplates, and the conveyor 209 is driven by a hydraulic motor 2.15 incircuit with the tank 201.

The upper conveyor 209 is vertically adjustable along the column 207relative to the cantilevered member 208 and in FIG. 5 it is shown in itshighest position. The conveyor 209 is conveniently guided and supportedduring its vertical movement. yIt will be manifest that if the piston ofcylinder 210 is retracted, it will pivot the linkage 211 about axis 216causing guide 212 to slide down its vertical slot 217. This willsimilarly cause linkage 218 to pivot about axis 219. Thus, upperconveyor 209 can easily be adjusted vertically. The cylinder 210 is, of

course, connected to a compressed air supply (not shown).

Linkage 218 is connected rvia a screw-threaded springloaded element 220`screw-engaging a stationary part of member 208 to a handwheel 221.Rotation of the handwheel 221 and element 220 adjusts and xes the topheight of conveyor 209, to suit various bundle heights. A scale 222allows the upper limiting position of conveyor 209 to be set accuratelyby the handwheel 221.

The tying unit is of the kind specified, and the pneumatically operatedneedle 223 is attached to the side of cantilevered member 208 in linewith the clipper box 224 which is suspended from the lower conveyor 204.

The upper conveyor 209 has an angled lead-in conveyor section 225 ofsimilar construction to the conveyor 209 but driven at a slightly fasterspeed than the latter so that a square bundle delivered to the machineis maintained.

The control panel for the machine is indicated at 226, and the requiredsolenoid-operated hydraulic and pneumatic valves (not shown) areaccessibly located in or around the bottom of column 207.

A motor-driven hydraulic pump is indicated at 227 and is supported ontank 201.

The vertical column 207 is hollow to recei-ve three verticallysuperimposed reels of twine T, and coiled clip metal C is stored in adispenser 228 suspended beneath the lower conveyor 204 The abovedescribed machine is therefore provided with hydraulic, pneumatic andelectricity supplies, and the sequence of operations can be adjusted andpre-set by the controls at panel 226.

Reference will now be made in particular to FIG. 4 which shows thepositioning of various limit switches and a photo-electric cell, and'toFIGS. 6 and 7 showing respectively the hydraulic and pneumatic circuitsof the machine.

The operation of the machine will rstly be described generally and thenin detailed step-by-step.

By turning the handwheel 221, the height of the top conveyor 209 is setagainst the scale 222 to suit the height of bundles B to be tied. If thedelivery line for the bundles is fixed, the machine must be positionedso that the tie coincides with the centre of the bundles B. These arethe only adjustments required when adjusting for different sized bundlesB. The twine T and clip metal C having been threaded and with thecontrols in the operating position, a squaredup bundle B is fed into themachine. The angled leadin 225 of the top conveyor 209 progressivelycompresses the bundle B until suilicient load is applied to providetraction. Twine T passing from needle `223 and held in clipper box 224,is contacted by the leading edge of the bundle B and forward motion ofthe bundle B causes the twine T to be wrapped around the bottom, leadingedge and top of the bundle B. Just prior to reaching the tying position,the trailing edge of the bundle B releases a limit switch which causesthe conveyor hydraulic motors 215 to go into slow speed. The bundle Bproceeds at reduced speed until the tying position is reached when aphoto-electric cell signals the conveyor motors 215 to stop.Simultaneously with the motors 215 stopping, the top conveyor 209 ispneumatically loaded by cylinder 210 and linkages 211 and 218 acting onguide 212 to further compress the bundle B and the needle 223 descends.The needle 223- enters the clipper box 224 and at the end of its stroke,a cycle is instigated which causes a clip to be formed to secure the twoends of the twine encircling the bundle B in known manner. The twine Tis then severed below the clip and as the tying unit returns to itsinitial state, the needle 223 ascends leaving twine T for the nextbundle secured in the clipper box 224.

As the needle 223 commences its ascent, the pneumatic loading of the topconveyor 209 is relieved and the conveyor motors 215 start up in highspeed. The tied bundle B is carried out of the machine and the nextbundle B entering causes the cycle to repeat.

The detailed operating sequence of the above described machine is asfollows:

(l) The po'wer for the machine is switched on, the pump 227 is renderedoperative and the needle and clipper controls are turned to automaticfunctioning. Solenoid 9 is energised thus driving the hydraulic motors215 and eecting high speed running of the conveyors 204 and 209.

(2) A bundle B enters between the conveyors 204 and 209 and operateslimit switch 230 thus placing the photoelectric cell 23-1 in control ofa slow speed solenoid 232.

(3) The bundle B breaks the photo-electric cell beam which sets thephoto-electric cell relay.

(4) Limit switch 233 is now tripped by the bundle B and takes over fromlimit switch 230.

(5) The limit switch 230 drops olf the trailing edge of thebundle Bcausing the solenoid 229 to be de-energised and solenoidv 232 to beenergised. l

(6) The bundle B now proceeds at slow speed until the photo-electriccell beam is Vre-made by the trailing edge of the bundle B. Solenoid 232is de-energised and solenoid 229 remains de-energised thus putting thevalve 234 controlled by the solenoids 229, 232 in aA condition at whichthe motors 215 and consequently the conveyors 204, 209 stop.

Air solenoids 235 and 236 are simultaneously energised to operate valves235V and 236V and the needle 223 descends and the double-acting cylinder210 causes downward movement of the conveyor 209 to apply extracornpression to the bundle B.

(7) Limit switch 237 is tripped as the needle 223 reaches the bottom ofits stroke and solenoid 238 is energised to operate valve 239 and causeforward motion of the clipper ram 240.

(8) At the end of the stroke of the ram 240, limit switch 241 isoperated to de-energise the solenoid 238 and energise air solenoid 242.The ram 240 commences its return stroke and operation of valve 242Vcauses a blast of air to be directed to the clipper box as indicated at243.

(9) At the end of the return stroke of the ram 240, a limit switch 244is operated to de-energise air solenoids 242, 236 and 235. The needle223 ascends, the extra compression applied by cylinder 210 to the topconveyor 209 is relieved and the air blast at 243 is cut-01T. v

(10) Limit switch 237 is released as the needle 223 ascends, and thesolenoid 229 is energised causing the conveyors 204 and 209 to run athigh speed.

(11) The bundle B is propelled out of the machine and the trailing edgethereof releases limit switch 233 resetting the control relays.

The machine is nowready to accept the next bundle B.

A limit switch 245 is arranged at the junction of conveyors 209 and 225to be operated by undue upward movement of the conveyor 225 tode-energise solenoids 229 and 232 and thus acts as a safety device tobrake the conveyor motors 2215 and stop the conveyors 204 and 209 if anoversized object attempts to enter the machine.

The pneumatic 'circuit has a connector 246 for connection to an airsupply, a lilter 247, and a manuallyoperable blow gun 248 connected tothe circuit by a flexible hose.

The hydraulic circuit incorporates a strainer 249 at the tank 201 and alter 250.

In a modification of the machines intended for faster throughput ofarticles, a two speed conveyor drive is incorporated, the method ofoperation being such that an article is conveyed rapidly to a locationup-stream of the tying station, when a'slow speed conveyor drive takesover to convey the article to its precise location at the tying station.In this 'modification when applied to the machine of FIGS. 1 to 3 thephoto-electric cell y110 is located adjacent the tying station and limitswitches 114 and 118 are omitted.

v`The invention is not limited to the tying of stacked carton blanks.The machine described is for example capable of tying certain otherarticles or bundles having slightly varying heights and varied trailingface configurations.

Due particularly to its in-line form of operation, the machine describedpermits a higher capacity in terms of rate of throughput ofarticles'than certain known forms of tying machines in one of which, forexample, an article is brought manually intothemachine along a givenentry path and is conveyed manually out of the machine on an exit pathat right angles to the entry path.

What is claimed is:

1. An article tying machine adapted for in-line operation, comprisingupper and lower conveyor means for positively holding and 4conveying anarticle linearly through the machine, a tying station within the run ofthe conveyor means incorporating a tying means including a needle andtwine for tying an article loc-ated at the tying station, a sensor meansfor sensing the passage of a trailing extremity of the article andemitting a stop signal operative to stop the conveyor means when saidtrailing extremity of the article is at a predetermined locationrelative to the line of action of said needle of said tying means, andmeans operative to restart the conveyor means when the article has beentied.

2. A machine as claimed in claim 1, further including guide means forsupporting said upper conveyor means in guided vvertical movementrelative to said lower conveyor means, an adjusting means for adjustingand limiting the height of said upper conveyor means above said lowerconveyor means, and pneumatic means for adjusting said upper conveyormeans vertically' relative to said lower conveyor means below its setheight to accommodate diierently-sized articles and to exert apredetermined pressure on the articles being moved through the machineby the conveyor means.

3. A m-achine as claimed in claim 2 in which said adjusting meansincludes a spring-loaded screw device, a linkage system operativelyinterconnecting said springloaded screw device between a stationary partof the machine and the vertic-ally-movable upper conveyor means.

4. A machine as claimed in claim 3, wherein said pneumatic meansincludes a pneumatic ram operatively connected to said linkage system toprovide the vertical adjustment of said upper conveyor means below itsset maximum height.

5. A machine as claimed in claim 2 further including two horizontallyextending members supporting said upper conveyor means and slidinglycarried by said guide means said adjusting means raising and loweringsaid horizontally extending members on said guide means.

6. A machine as claimed in claim 2 further including a cantileveredmember supporting said upper conveyor means, said upper conveyor meansbeing slidingly carried by said guide means for vertical movementrelative to said cantilevered member, and said adjusting means raisingand lowering said upper conveyor means on said guide means.

7. A machine as claimed in claim 1 in which said upper conveyor meansincludes an angled conveyor means at the feed-in end of the machine,means for moving said angled conveyor means faster than said upper andlower conveyor means to avoid any tendency of said angled conveyor meansto retard the article, a safety means operatively associated with saidangled conveyor means for stopping the machine if an article ofexcessive size is presented to the machine.

8. A machine as claimed in claim 1 further including a motor meansincorporating a brake means operatively connected to said upper andlower conveyor means for driving same.

9. A machine as claimed in claim 1, further including variable speedhydraulic motor means operatively connected to said upper and lowerconveyor means for driving same.

10. A machine as claimed in claim 1 wherein said tying means includesneedle and twine supply supported by said upper conveyor means and aclipper land metal strip supply supported by said lower conveyor means.

11. A machine as claimed in claim 1, further including a wheeled supportfor the machine so that it can be readily moved.

12. A machine as claimed in claim 1, further including limit switchmeans for effecting said feeding, stopping, tying and delivery functionsin pre-set timed relationship, said limit switch means being operated bymovements of the article and said needle of said tying means.

References Cited UNITED STATES PATENTS 2,662,468 12/ 1953 Shenigo.

2,818,795 1/ 1958 Gustafson 100-4 3,077,157 2/ 1963 Gordon 100-43,114,308 12/1963 Saxton et al. 100--7 XR 3,115,085 12/1963 Van de Bilt100-7 XR 13,330,205 7/ 1967 Smith 100-4 BILLY I. WILHITE, PrimaryExaminer U.S. Cl. X.R. 10Q- 3, 7,19, 53,153

